Remove the EGR valve as per the manual instructions, clean and refit. If you can't do this I suggest getting a decent mechanic to do it. Its an easy job just don't tear the gasket if you don;t have a spare one.
Ok thanks but i have had a look and there is a plate its a kind of a flat pipe which apparently needs cleaning aswell it gets full of carbon i can see it clearly its located under the injectors any idears
